The proposed UMASS Center for Translational Research on Human Immunology and Biodefense is a comprehensive, interdepartmental collaboration to address, as its overall scientific theme, the role of human T lymphocyte responses in the immunopathogenesis of and protection from category A-C viral pathogens. The Center encompasses senior and junior investigators with significant prior expertise in human immunology and research on biodefense pathogens, including translation to clinical studies, and is organized around the following components: Project 1 (Poxviruses) will define immunodominant human T cell epitopes of vaccinia virus as markers of vaccine efficacy and advance knowledge toward the development of improved smallpox vaccines. Project 2 (Hantaviruses) will define human immune responses associated with immunopathogenesis of hemorrhagic fever with renal syndrome. Project 3 (Flaviviruses) will define protective and immunopathological cross-reactive human T cell responses to sequential virus infections. The Technical Development Component (TDC) will develop novel solid-phase array and proteomics technologies for application in T cell epitope identification, detection and enumeration of virus-specific T cells, and identification of biomarkers of protective or pathological T cell responses. Core facilities will provide flow cytometry, MHC class I production, MHC class II production, and program administration services for use by the research projects and TDC. A Pilot Projects component will support pilot funding of promising novel research concepts proposed by UMMS faculty. An Education component will support short-term training of non-Center investigators. The proposed Center will address important NIAID research priorities related to these biodefense pathogens as well as career development for young investigators. The Center will facilitate synergistic interactions between the various investigators, to be assessed by periodic internal and external review that will greatly enhance the overall research productivity.